Sampling probe



July 26, 1966 w, DECKER 3,262,318

SAMPLING PROBE Filed Aug. 5, 1964 lllll Ill/Ill INVENTOR ROBERT W. DECKER ATTORNEY United States Patent 3,262,318 SAMPLING PROBE Robert W. Decker, Washington, D.C. (11313 Frederick Ave., Beltsville, Md.) Filed Aug. 5, 1964, Ser. No. 387,567 15 Claims. (Cl. 73-421) The present invention relates to a sampling probe, and more particularly to a sampling probe having inner and outer tubes with helical vanes between the tubes at the end of the inner tube.

Many granular materials are stored in large bins, and grain is a notable example of such materials. Where grain is stored, the sizes of individual grains vary, and the distribution of the grain is not uniform. It is also a fact that when the grain is stored, it contains trash and moisture, and this moisture is carried through the grain by natural air currents within the storage bin, the natural air currents tending to bring the moisture to the upper part of the storage bin. The moisture caused spoilage of the grain, beginning at or near the upper surface, and in order to avoid this many storage bins utilize fans which cause air currents to flow from above the grain bin downwardly through the grain. This results in the moisture being carried to the lower portion of the bin, so that spoilage begins, with these bins, at the bottom most level thereof; thus initially spoilage is generally at the bottom two inches of the grain. Of course, once spoilage commences, it progresses through the body of the grain.

To determine the presence of spoilage and the variation of grain sizes in the bins, a sampling probe is forced downwardly through the grain, this sampling probe comprising inner and outer tubes, with the outer tube extending beyond the inner tube. Air under pressure is forced downwardly in the space between the tubes, and a suction is applied to the inner tube, the intent being to draw the grain upwardly through the inner tube and to supply in the space between the tubes, the airnecessary to permit the grain to flow with the air current induced by the suction. been subject to a number of deficiencies. They did not select all grain sizes, but instead removed from the bin a false sampling over-burdened with larger grains and therefore did not reveal the true proportion of smaller grain and light trash in the bin. It has been discovered that this was due to the fact that lighter grain and trash were blown away from the end of the outer tube by the air under pressure blown into the bin between the two tubes. As the sampling probe was forced downwardly, clogging of the space between the two tubes was an all too frequent occurrence. Sampling probes heretofore known were not able to sample the entire bin, and did not reliably sample the bottom most levels of the bin, where spoilage begins.

It is an object of the present invention to provide a sampling probe which will sample all grain sizes to thereby give an accurate sampling.

Another object of the present invention is the provision of a sampling probe which avoids grain clogging of the probe.

Still another object of the present invention is to provide a sampling probe which may be readily advanced through a bin of grain, or the like.

A further object of the present invention is the provision of a sampling probe which will provide a sample of the grain from the top to the bottom most level of a grain bin.

A still further object of the present invention is to .provide a sampling probe which will take a full, as distinguished from a diminished, sample of grain from a bin.

Other objects and many of the attendant advantages of Such sampling probes have heretofore ice the present invention will be readily understood from the following specification and drawings, wherein:

FIG. 1 is a view of a sampling probe in a bin of grain, or the like.

FIG. 2 is a longitudinal cross sectional view of a sampling probe in accordance with the present invention.

FIG. 3 is an end View looking into the sampling probe of FIG. 2.

FIG. 4 is a cross sectional view taken on the line 4-4 of FIG. 2.

FIG. 5 is an elevational view of the blank of a vane used in the sampling probe of FIG. 2.

FIG. 6 is a plan view of a vane blank.

Referring now to the drawings, wherein like or corresponding numerals are used to designate like or corresponding parts throughout the several views, there is shown in FIG. 1 a sampling probe generally designated 10 positioned in a bin of grain, or the like, the probe 10 comprising an outer tube 11 and an inner tube 21. A force of air, or other gas, under pressure is connected to the space between the outer tube 11 and the inner tube 21, and a force of reduced pressure, such as a suction line, is connected to the inner tube 21. Consequently, air is blown into the body of the grain from between the tubes 11 and 21, and substantially the same volume of air containing grain samples is sucked upwardly through the inner tube 21.

Referring now to FIG. 2, the sampling probe 10 may be seen to comprise an outer tube 11 having an upward extension 12 soldered or otherwise connected to it. Outer tube 11 is of substantially uniform diameter, both inner and outer, until a point 13 adjacent the end 14 thereof, the inner diameter of outer tube 11 increasing from point 13 to end 14. The end 14 of outer tube 11 is provided with a plurality of notches 16, the notches 16 being spaced by lands 17. This construction of the end portion of outer tube 11 provides a relatively sharp, notched or scalloped wedging edge permitting the ready advance of the sampling probe into the mass of grain.

The inner tube 21 is positioned concentrically within the outer tube 11 by a series of equally peripherally spaced spacers 22, three being preferred as shown in FIG. 4. The spacers 22 are welded to the outer surface of the inner tube 21 and permit air to flow in the space between outer tube 11 and inner tube 21. The end 23 of inner tube 21 is provided with spaced notches 26 having lands 27 between them. A plurality of equally spaced vanes 25 extend between the outer surface of inner tube 21 and the inner surface of outer tube 11, as may be seen in FIGS. 2 and 3. Each vane 25 extends in a generally helical fashion from a land 27.

There is shown in FIG. 5 a plan view of a blank 25B, this blank being fiat or planar, and having a slightly undulating shape. In FIG. 6 there is shown the blank 25B after it has been curved to a generally part-cylindrical configuration.

In operation, the sampling probe 10 is advanced through the granular material, such as grain, to be sampled, with the end 14 of the outer tube 11 tending to wedge its way through the grain. With suction and pressure connections as above described, air will flow into the space between the inner tube 21 and the outer tube 11 and upon reaching the vanes 25, will be given a rotary motion by these vanes. In addition, due to the fact that air is being Withdrawn upwardly through the inner tube 21, there will be a pressure drop towards the center of the probe 10, in comparison to the pressure adjacent the end 23 of the inner tube 21 near the walls of the outer tube 11. As a result, the air flowing between the two tubes will reverse its direction in a relatively short axial distance, thus permitting the grain which is slightly above the end 14 to be readily drawn upwardly into the inner tube 21, this action being assisted by notches 26. Because the air under pressure is not blown out of the end of outer tube 11, nor does it reach the end of outer tube 11 with any substantial velocity, grain does not become packed between the two tubes, and a true sample of all grain sizes and trash is removed through the inner tube 21. The sample of grain (and trash) taken is a full sample, and the sampling probe will remove grain from the bottom most level of the bin.

In the preferred embodiment, the inner and outer tubes are one inch and one and one half inches outside diameter, respectively with walls thicknesses of .035 inch. The notches 26 are circular, with inch radius and are spaced 45 degrees apart, these notches extending upwardly approximately one eighth inch. The notches 16 are of a one quarter inch radius and extend upwardly approximately three sixteenths inch, the notches 16 also being spaced apart 45 degrees. The end 23 of inner tube 21 is spaced inwardly from the end 14 of outer tube 11 a distance of three and one half inches, or approximately 3.75 times the inner diameter of inner tube 21. The radius of curvature of blank 25B is one and one eighth inches.

It will be obvious to those skilled in the art that various changes may be made without departing from the spirit of the invention and therefore the invention is not limited to what is shown in the drawings and described in the specification but only as indicated in the appended claims.

What is claimed is:

1. A sampling probe comprising an outer tube of substantially uniform inner diameter to a point adjacent the end thereof and having an increasing inner diameter from said point to the end, said end having spaced notches therein, an inner tube positioned within said outer tube, spacer means between said tubes for maintaining said tubes substantially concentric and permitting air to flow therebetween, the end of said inner tube having spaced notches therein with lands between the notches, equally spaced vanes extending between the outer surface of said inner tube and the inner surface of said outer tube, each vane extending helically from a land at the end of said inner tube, said outer tube extending beyond the end of said inner tube approximately 3.5-4 diameters of said inner tube.

2. A sampling probe comprising an outer tube of substantially uniform inner diameter to a point adjacent the end thereof and having an increasing inner diameter from said point to the end, said end having spaced notches therein, an inner tube positioned within said outer tube, spacer means between said tubes for maintaining said tubes substantially concentric and permitting air to flow therebetween, the end of said inner tube having spaced notches therein with lands between the notches, equally spaced vanes extending between the outer surface of said inner tube and the inner surface of said outer tube, each vane extending helically from a land at the end of said inner tube, said outer tube extending beyond the end of said inner tube.

3. A sampling probe comprising an outer tube of substantially uniform inner diameter to a point adjacent the end thereof and having an increasing inner diameter from said point to the end, an inner tube positioned within said outer tube, spacer means between said tubes for maintaining said tubes substantially concentric and permitting air to flow therebetween, the end of said inner tube having spaced notches therein with lands between the notches, equally spaced vanes extending between the outer surface of said inner tube and the inner surface of said outer tube, each vane extending helically from a land at the end of said inner tube, said outer tube extending beyond the end of said inner tube.

4. A sampling probe comprising an outer tube, an inner tube positioned within said outer tube, spacer means between said tubes for maintaining said tubes substantially concentric and permitting air to flow therebetween, the end of said inner tube having spaced notches therein with lands between the notches, equally spaced vanes extending between the outer surface of said inner tube and the inner surface of said outer tube, each vane extending helically from a land at the end of said inner tube, said outer tube extending beyond the end of said inner tube.

5. A sampling probe comprising an outer tube, an inner tube positioned within said outer tube, means for joining said tubes and permitting air to flow therebetween, the end of said inner tube having spaced notches therein with lands between the notches, equally spaced vanes extending between the outer surface of said inner tube and the inner surface of said outer tube, each vane extending helically from a land at the end of said inner tube, said outer tube extending beyond the end of said inner tube.

6. A sampling probe comprising an outer tube, an inner tube positioned within said outer tube, means for joining said tubes and permitting air to flow therebetween, spaced vanes extending between the outer surface of said inner tube and the inner surface of said outer tube, each vane extending helically from the end of said inner tube, said outer tube extending beyond the end of said inner tube.

7. A sampling probe comprising an outer tube, an inner tube positioned within said outer tube, means for joining said tubes and permitting air to flow therebetween, spaced vanes extending between the outer surface of said inner tube and the inner surface of said outer tube, each vane extending helically from the end of said inner tube.

8. A sampling probe comprising an outer tube, an inner tube positioned within said outer tube, means for holding said tubes in assembled relationship and permitting air to flow therebetween, spaced vanes extending in the space between said tubes, each vane extending helically from substantially the end of said inner tube, said outer tube extending beyond the end of said inner tube.

9. A sampling probe comprising an outer tube, an inner tube positioned within said outer tube, means for holding said tubes in assembled relationship and permitting air to flow therebetween, spaced vanes extending in the space between said tubes, each vane extending helically from substantially the end of said inner tube.

10. A sampling probe comprising an inner tube and an outer tube, an axially extending space between said tubes adapted to be connected with a source of gas under pressure, said inner tube adapted to be connected with a point of reduced pressure, and means in the said space for causing gas issuing therefrom to have a component of velocity in a circumferential direction.

11. The sampling probe of claim 10, said means comprising vanes.

12. The sampling probe of claim 10, said tubes being concentric and said means comprising vanes.

13. The sampling probe of claim 12, said inner tube terminating within said outer tube.

14. The sampling probe of claim 13, said outer tube having wedging means on the end thereof.

15. The sampling probe of claim 10, said outer tube having wedging means on the outer end thereof.

References Cited by the Examiner UNITED STATES PATENTS 1,276,653 8/1918 Herbert et al. 302-46 X 2,771,776 11/1956 Haven 73--421 3,153,344 10/1964 Lawrence et a1. 73-425 LOUIS R. PRINCE, Primary Examiner. 

10. A SAMPLING PROBE COMPRISING AN INNER TUBE AND AN OUTER TUBE, AN AXIALLY EXTENDING SPACE BETWEEN SAID TUBES ADAPTED TO BE CONNECTED WITH A SOURCE OF GAS UNDER PRESSURE, SAID INNER TUBE ADAPTED TO BE CONNECTED WITH A POINT OF REDUCED PRESSURE, AND MEANS IN THE SAID SPACE FOR CAUSING GAS ISSUING THEREFROM TO HAVE A COMPONENT OF VELOCITY IN A CIRCUMFERENTIAL DIRECTION. 